In spiders, where as a rule the sexes do not differ much from each other in color, the males are often of a darker shade than the females. “In some species, however, the difference is conspicuous; thus the female of _Sparassus smaragdulus_ is dullish green, whilst the adult male has the abdomen of a fine yellow with three longitudinal stripes of rich red.” Darwin believes that sexual selection must take place in this group, because Canestrini has observed that the males fight for the possession of the females. He has also stated that the males pay court to the female, and that she rejects some of the males who court her, and sometimes devours them, until finally one is chosen. Darwin believed, on this evidence, that the difference in color of the sexes had been acquired by sexual selection, “though we have here not the best kind of evidence—the display by the male of his ornaments.” This evidence has, however, now been supplied through the interesting observations of Mr. and Mrs. Peckham. These accurate observers have studied the courtship of the male, and observed that during the process, he twists and turns his body in such a way as to show to best advantage his colors to the female. From their account this certainly appears to be the result of his movements, but whether this is really the case, and whether the female makes any choice amongst her suitors, according to whether they are more or less brilliantly marked, we are absolutely ignorant. The following account given by Darwin should not pass unnoticed:— “The male is generally much smaller than the female, sometimes to an extraordinary degree, and he is forced to be extremely cautious in making his advances, as the female often carries her coyness to a dangerous pitch. De Geer saw a male that ‘in the midst of his preparatory caresses was seized by the object of his attentions, enveloped by her in a web and then devoured, a sight which, as he adds, filled him with horror and indignation.’ The Rev. O. P. Cambridge accounts in the following manner for the extreme smallness of the male in the genus Nephila. ‘M. Vinson gives a graphic account of the agile way in which the diminutive male escapes from the ferocity of the female, by gliding about and playing hide and seek over her body and along her gigantic limbs: in such a pursuit it is evident that the chances of escape would be in favor of the smallest males, while the larger ones would fall early victims; thus gradually a diminutive race of males would be selected, until at last they would dwindle to the smallest possible size compatible with the exercise of their generative functions,—in fact probably to the size we now see them, _i.e._ so small as to be a sort of parasite upon the female, and either beneath her notice, or too agile and too small for her to catch without great difficulty.’”